The present invention relates to surgical clamping or grasping instruments for endoscopic or open surgery.
Surgical clamps that can be detached from their dedicated actuators have been available for some time. These clamps are typically spring loaded, i.e. they depend upon the force of an integral spring to remain closed, and are opened by xe2x80x9csqueezingxe2x80x9d the proximal end of the jaw assemblies (Refer to Prior Art, FIG. 1a and FIG. 1b). Clamp delivery devices consist primarily of dedicated xe2x80x9cpliers typexe2x80x9d actuators that squeeze the clamp open, place the clamp at the desired location, and then release the clamp which then closes under integral spring pressure.
During certain surgical procedures, it may be necessary to temporarily and securely occlude body conduits (such as blood vessels and the like) of relatively large size, which due to disease, may have uneven wall thickness, or may be partially obstructed or stenotic. In open surgery, when access to the site is not limited, standard vascular type clamps (utilizing ring handles) are typically applied. Clamping force is increased until the body conduits are effectively and securely occluded, and then locked by means of ratchets. In endoscopic surgery, clamps are typically introduced to the surgery site through access ports (small openings made by a surgeon, and/or through natural existing body openings). However, it is desirable to reduce the number of openings made by the surgeon, as well as to reduce instrument clutter at the surgical site itself. Standard vascular type clamps do not lend themselves to reducing the number of surgical access ports and/or reducing instrument clutter at a surgical site. Spring loaded clamps have the limitation of not delivering sufficient clamping force to overcome the non-uniform thickness of body conduit walls to provide effective occlusion. Additionally, spring loaded clamps have a tendency of dislodging (slipping off) when disturbed, due to insufficient clamping force, thus risking patient safety. The tendency of dislodging (slipping off) applies, as well, when clamps are used to temporarily retract tissue.
The jaws of spring-loaded clamps are normally fully closed (exacting full clamping force as provided by spring tension) when detached from their delivery device, thus the clamping force cannot be varied by the surgeon. In order to apply differing clamping forces necessary for diverse medical procedures, many clamps with identical jaws and different spring tension must be available and used. One variable related to clamp effectiveness is tissue thickness (the thicker the tissue, the greater the resulting clamping force). Clamping force is limited by the spring tension, which is derived from the spring""s physical size. If the spring physical size is large to provide greater clamping force, other aspects of surgery must be considered. Access ports typically have small diameters (the overall philosophy of endoscopic surgery is to make as few access port openings as possible, with the smallest diameter as possible), thus the larger sized springs required for greater clamping force are difficult to pass through the access port(s) to the surgical site. Additionally, the ability of the delivery method to squeeze the clamp open is limited; the greater spring tension required, the more difficult it becomes to remotely open the clamp.
What is desired, therefore, is a surgical clamp which delivers sufficient clamping force to overcome the non-uniform thickness of body conduit walls to provide effective occlusion, which does not have a tendency of dislodging (slipping off) when disturbed, which allows the clamping force to be varied by the surgeon, and which provides a clamping force which is not limited by spring tension.
Accordingly, it is an object of the present invention to provide a surgical clamp which delivers sufficient clamping force to overcome the non-uniform thickness of body conduit walls to provide effective occlusion.
Another object of the present invention is to provide a surgical clamp having the above characteristics and which does not have a tendency of dislodging (slipping off) when disturbed.
A further object of the present invention is to provide a surgical clamp having the above characteristics and which allows the clamping force to be varied by the surgeon.
Still another object of the present invention is to provide a surgical clamp having the above characteristics and which provides a clamping force which is not limited by spring tension.
These and other objects of the present invention are achieved by provision of a surgical clamp system including a clamp, a delivery/retrieval device, and an actuator. The clamp includes a pair of jaws actuatable relative to each other from a fully open to a fully closed position. The delivery/retrieval device is detachably connected to the clamp, and is operable by a surgeon to deploy the clamp, retrieve the clamp, or both. The actuator cooperates with the delivery/retrieval device and engages the clamp, and is operable by the surgeon to open and close the jaws of the clamp. The delivery/retrieval device and the actuator are operable to securely lock the jaws of the clamp in any position between the fully open and the fully closed positions, both during and after being detached from the delivery/retrieval device.
The pair of jaws of the clamp may be configured such that both are movable, or such that one is movable and the other is stationary. In one embodiment, the pair of jaws of the clamp may be substantially parallel to each other in any position between the fully open and the fully closed positions.
In one particular embodiment, the clamp includes a push-pull rod connected at one end to at least one of the pair of jaws of the clamp, a threaded screw connected to an end of the push-pull rod opposite to the end connected to the jaw or jaws, and a threaded nut engaging the screw, the nut being rotatable with respect to the screw in order to cause axial displacement of the screw and actuation of the pair of jaws. The nut is externally engageable by the actuator. In this embodiment, the jaws of the clamp are securely locked in any position between the fully open and the fully closed positions, both during and after being detached from the delivery/retrieval device by cooperation of the screw and the nut. It should be understood that while a screw/nut drive is described in the detailed example presented herein, other configurations for actuating and/or locking the jaws are also possible, such as a worm gear/drive gear arrangement, ratcheted push-pull rod, or the like.
In one particular embodiment, the delivery/retrieval device includes an elongated hollow shaft, a distal end of which is detachably connectable to the clamp, and a proximal end of which is adapted to receive the actuator. Preferably, the delivery/retrieval device is detachably connectable to the clamp by a bayonet connection.
In one particular embodiment, the actuator includes an elongated shaft having a distal end which rotatably engages the clamp in order to cause actuation of the pair of jaws of the clamp, and a proximal end having an externally accessible termination for permitting rotation of the shaft. Preferably, the distal end of the shaft rotatably engages the nut of the clamp.